Inserted-tooth saw



April 1, 1930.

E. c. ORR

INSERTED. TOOTH SAW Filed June 27, 1927 2 Sheets-Sheet l EZzj'a/z C OrrW April 1, 1930. E. c. ORR 1,752,541

INSERTED TOOTH SAW.

Filed June 27, 1927 2 Sheets-Sheet 2 Eli ah 60H" gwwntoc v Patented Apr.1, 1930 UNITED STATES PATENT OFFICE Emma. c. one, or SEATTLE, wnsnmeron,ASSIGNOR TO 01m saw 'roorn GRINDER 00., or SEATTLE, WASHINGTON, ACORPORATION or WASHINGTON INSERTED-TOOTH SAW Application filed June 27,1927. Serial No. 201,629.

My invention relates to inserted teeth saws, and consists of certainimprovements in construction whereby two teeth may be inserted in onerecess in the saw center, and

whereby also the two teeth of a .pair may bemade of different types ordifferent 0on struction, thuscooperating to produce a more perfect and soot ut ,The object ;of;my 1nven tion is to so improve such saws as bothto increase their capacity and to improve the quality'ot work done. I P

My [nventionis more particularly designed for application to c o c sa s,by t s m aning aw wh h re in ded. p r larly forcutting transverselyofthe fibers or grainof-the wood.

My invention consists .in theimprovements of const ucti n of whic ypi ampl r shown in the drawings and described in the ollowing spec at oFigure lshows a section of a sawcenter :made iniacco da e w th y n e t afew of mywimproved teeth beingshown in place. Figur whom apai of t e moin a fragment of a sa ce te Figures 3 and .4 illustrate, respectively,the

raker tooth 2 and the scoring teeth 3 by sec- 'tionstaken, respectively,on the lines 3.3 and H of'Figure'Q. I

Figures 5 and 7 are face views similar to "Figure .2, showing o he h pe0f t Figures 6 and 8 are sections taken, respectively, on lines 6-61flBd8- '8 of Figures 5 and v7 .1 r Y QFigure 19 is an end view of thetooth 3hOW i igu e 7 ands j One characteristicof my invention is the placing oftwo teethinone. recess in the saw center orzd s b t being {held in Placey the same/lo ki g pie Another characterlstic which may not in all casesbe used,-cons stsin making the teeth of each pair "of difierent type,each adapted to perform difierent functions and cooperatfor instance asply-wood, where at least part of the wood has its fibers cut crosswise.The purpose of the particular shape of teeth shown has been to provide asaw whichwill make a clean and smooth out in such materials.

In the drawings, 1 indicates the center or mam body portion of acircular saw having recesses 10 in its periphery for the reception ofinserted teeth. The edge surfaces of contacting parts of the saw centerand the teeth parts are supposed to be of complemental ridge and channelshapes, as is standard practice in inserted tooth saws. Specificdescription of this feature is not deemed necessary, as the same is wellunderstood in theart and any type of interlocking edge shape foundsuflicient may be employed.

The outline of the teeth-receiving recesses 10 employed is circulararcuate, the are being greater than 1 degreesin-extent. Theedge sections11 of the saw center between the teeth-receiving recesses 10 arepreferably given the same interlocking rib and groove construction, andhave, in the saw illustrated,

been given an arcuate contour, outwardly convex. The arcuate shape atthis point l consider convenient but not essential. i

The two types of teeth 2 and 3 employed in each pair are alike in themeans employed 4 n securing them in place. Each has an arcuate shank 20and 30, respectively,on its outer or convex edge made complemental tothe edge walls of the receiving recess 10.

The end faces of these shanks contact, ornap-v proximate to contact, ator about onthe middle of the extent of the recess wall, as indi cated at24.

v The shank of each tooth and the recess wall are provided withinterlocking proj'ections and recesses, as indicated at 21, by whichmeans arcuate sliding movement between the two is prevented. It .ispreferred that these interlocking members be located at different pointsfor the respective teeth, so that they 7 must be properly positionedwhen inserted.

The teeth-locking and holding members 4 are disks havlng interlockingperipheral edges. and being of circular outline cut away at one side topermit of insertion, and also 1 to conform to the outline of thechip-receiving throat between the teeth. This locking disk is preferablyslotted so as to provide some resiliency and to make it possible totighten it in case it fits loosely. I have shown two holes 40, which mayserve to receive a spanner whereby to turn it, these being joined to acentral hole 43 by slots 41 and the central hole connected with the edgeby a slot 42. These details are however not strictly essential.

After insertion, or if the fit be loose, a rivet placed in the centralhole 43 and hammered down, will expand and produce a tight fit. It willalso serve as a supporting or stiffening connection between oppositearms of the disk 4 to bear the thrust of the leading tooth 3.

The direction of revolution of the saw is indicated by the arrow 9 inFigures 1, 2 and 7. The leading tooth 3 is of the type called a cuttingtooth; that is, it is designed to cut the fibers at the edge of thekerf, while the following tooth 2 is a raker tooth, or one designed toact as a chisel to remove the chip. It is, of course, evident that bothteeth might be made exactly alike as to their cutting form and edges, ifthis fitted the service desired, but for the purpose hereinbeforespecifically mentioned, the differences of construction herein mentionedare desirable.

For this specific service the teeth 3 are given a cutting edge 35 ateach side, and th1s edge is inclined relative to the path of movement,the

. advancing corner 34 being lower than the following corner 33. Inconsequence, this tooth makes a draw out and will, as a result, cut moresmoothly than would another ty 9 of tooth in which the leading cornerwas t ie higher.

The tooth 3 illustrated in Figures 2 and 4; has a smooth, uninterruptededge. The tooth shown in Figures 7, 8 and 9 is the same except that ithas channels 36 in the outer side faces of its wings, thus providingcutting edges acting as the bit of a plane to smooth up the side wallsof the kerf.

The tooth 3 illustrated in Figures 5 and 6, is divided into two chiselends 37, one following after the other, and each cutting or scoring itsside of the kerf. As a result of using the side scoring or cutting teeth3 and the raker teeth 2, cleaner cutting is secured, especially inmaterial which is difficult to cut smoothly.

If the raker teeth 2 be positioned so that their cutting edges are theleast bit nearer the saw center than the outermost tips of the cutterteeth 3, an exceptionally smooth out will be produced. This result isalso contributed to by the formation of planing edges by the grooves 36on the side faces of the teeth 3.

By my present invention in which two teeth are secured in one recess, Iam able to mount more teeth upon a saw of given size,

which in itself contributes to more rapid and smooth cutting at a givenspeed.

By using teeth of two types, namely cutters and rakers, I am able toproduce results in smoothness of out directly by the saw, not obtainableby any saw known to me and fairly comparable with results heretoforeproduced only by using a special finishing step after cutting with asaw. To secure greatest smoothness of cut I prefer that the acting edgesof the cutter teeth 3 extend outwardly a sufficient distance from thecenter of the saw that the cutting edges of the cutter teeth first severthefibers at the edges of the kerf and the raker teeth then remove athin shaving.

A saw of the type contemplated may be used for cutting thin stock, asply wood, in which case the ability to use a high rate of feed is highlydesirable. If the side cutting teeth of complemental pairs are placedvery far ahead of the raker tooth which removes the wood cut across bythe side cutting teeth, a high rate of feed causes rough cutting.

The ideal relative position for the two complemental teeth of any air,is a projection of the side cutting tooth eyond the raker tooth anamount equivalent to the feed of the material during the time requiredfor the saw to turn through the are which separates the tips of the twoteeth. Referring to the drawings, this are would be the distance betweenthe adjacent tips of teeth 2 and 3 of a pair. When this conditionobtains, the side cutting teeth out as deep as the rakers and no fibersare torn across at the sides of the kerf.

If the teeth of a saw are positioned to secure this result for a givenrate of feed, a higher rate of feed causes tearing across of the fibersfor a depth corresponding with the amount of increased feed. It isevident that if the raker tooth follows closely behind its side cuttingtooth, this de th of tearing will be much less than if it ollows at amuch greater angular distance. It is therefore highly important, inorder to adapt it saw to widely differing rates of feed, that each rakertooth follow as closely as feasible behind its cutter tooth.

To secure this close spacing with an inserted tooth saw it is necessarythat both teeth of a pair be placed in a common recess in the saw body.It is also desirable that their outermost cutting tips be extendedtowards each other. By this expedient I get the two cutting tips closetogether and by projecting the cutting teeth but little more than isnecessary for a slow feed, they are projected enough for a high feed andthe saw will cut smoothly for all practicable rates of feed.

What I claim as my invention is:

1. A circular saw having tooth receiving recesses, complemental teethfor each recess and teeth locking means, the tooth which is positionedahead of its mate having peripheral cutting edges on the plane of itsside faces and inclined slightly to the path of movement to therebyproduce a draw out, the following tooth of the pairbeing a raker toothpositioned to act close behind its com panion and projected in a radialdirection to cut to approximately the same depth as the side cuttingtooth.

2. A circular saw having tooth receiving recesses, complemental teethfor each recess, and a common securing means for the teeth of each pair,the leading tooth of each pair having cutting edges, acting to out thefibers at the side margins of the kerf and the following tooth of eachpair being a chisel pointed tooth adapted to remove the chip which hasbeen cut across by the leading tooth and having its cutting pointpositioned close behind the leading tooth.

Signed at Seattle, King County, Washing- :3 ton, this 3rd day of June1927.

ELIJAH C. ORR.

